1+12+13+52+82=?

1+12+13+52+82=? ( )+20=( )-40=12+( )=82-( )=52 ( )+20=( )-40=12+( )=82-( )=52 82/15+52/15应用乘法分配率怎样算如72/12+32/12=? 12+22+32+42+52+62+72+82+…+n2=n(n+1)(2n+1)/6 13+23+33+43+53+63+…n3=n2(n+1)2/4 1*2+2*3+3*4+4*5+5*6+6*7+…+n(n+1)=n(n+1)(n+2)/3 直截面体积的概念? 1/√52×√13= 1+2+3+4+5+6+7+8+9+…+n=n(n+1)/2 1+3+5+7+9+11+13+15+…+(2n-1)=n2 2+4+6+8+10+12+14+…+(2n)=n(n+1) 12+1+2+3+4+5+6+7+8+9+…+n=n(n+1)/2 1+3+5+7+9+11+13+15+…+(2n-1)=n2 2+4+6+8+10+12+14+…+(2n)=n(n+1) 12+22+32+42+52+62+72+82+…+n2=n(n+1)(2n+1)/6 13+ 1+5+4+9+6+5+4+4+13+25+60+23+78+56+10+52+36+12+13+43+53+82+92+72+62+8997+95+4+69+2+2等于多少? 1+2+5+653+6+9+8+7+5+49+4+92+82+5+52+5869+56969+36+36+5555+595+659+9595+595+959989+5956959+559565+566+565+5+56559+59589+9999+9985+9585+5596+5655+5+566+5665+41+12+12+13+2+6595+999999=? 4*12=48 100-48=52 52/13=4怎么列综合算式 数学题：5X-11=X-52*12+13 52×13分之1×25分之12等于多少 数字逻辑题 13 17 29 52 82数字逻辑题13 ,17 ,29 ,52,82 ,有什么规律么 12 13 16 25 52 每题移动1根火柴,使算式正确.21+35=68.51-37=82 52+62=30 简单的百分数计算:::::::::41/53 =12/53 =15/72 =20/72 =10/72 =27/72 =44/56 =6/56 =37/52 =14/52 =1/52 =42/58 =11/58 =5/58 =10/57 =4/57 =43/57 =13/52 =21/52 =18/52 =40/52 =8/52 =4/52 =8/58 =6/58 =44/58 =4/50 =28/50 =18/50 = 森德拉姆的正方形筛子 4 7 10 13 16 19 22 .7 12 17 22 27 32 37 .10 17 24 31 38 45 52 .13 22 31 40 49 58 67 .16 27 38 49 60 71 82 .（1）这个“正方形筛子”的每一行有什么特点?每一列呢?（2）“正方形筛子”中位于 52-(7*x-x/1/3)*2=12